The Standing Committee agreed in February 2015 to request EFSA for a complete Pest Risk Assessment before taking a decision about the future regulatory status of this pest in the EU (EU COM, 2015). This complete PRA was published in 2016 (EFSA-PLH 2016). Data of the presence of this pest on the EU territory are available in EPPO Global Database (https://gd.eppo.int/). The nematode is sporadically present in the majority of EU Member States (EFSA, 2014).

HOST PLANT N°1: Gladiolus (1GLAG) for the Ornamental sector.

Origin of the listing:

IIA2AWG

Plants for planting:

Miniature cultivars and their hybrids intended for planting

3 - Is the pest already listed in a PM4 standard on the concerned host plant?

No

Conclusion:

Evaluation continues

4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):

Yes

Conclusion:

Candidate

Justification:

D. destructor attacks a wide range of ornamental and vegetable species, however EFSA quotes only two references, one suggesting the nematodes from Gladiolus were probably feeding on fungi rather than the roots, and the other that there was inconclusive evidence as a host and D. destructor was able to multiply after bulb storage, but maybe on Botrytis. The conclusion was of unclear status but Gladiolus is most likely not a host plant (EFSA-PLH 2016). However experts reported information from the NL inspection services saying that Gladiolus, especially Gladiolus nanus and Gladiolus x colvillei, is a host plant.

5 - Economic impact:

Are there documented reports of any economic impact on the host?

Yes

Justification:

The reproductive potential of D. destructor is high. It can be assumed that even a small population of D. destructor, present in the soil at the beginning of the growing season, could develop into a very large population causing severe damage to infested host plant. D. destructor can cause significant damage to the below-ground parts (roots, tubers, bulbs) of host crops such as potato and several ornamental plants. It reduces harvest yields of host crops and causes additional damage during storage. In recent years, potato tuber nematodes have caused serious problems on iris and garlic crops in Japan (EFSA, 2014). Experts reported experience from the NL inspection service indicating that Gladiolus are impacted, and considered that it is sufficient to justify the RNQP listing of this pest/host combination. However, D. destructor cannot survive dessication which may be one of the reasons why this species is much less of a problem than D. dipsaci.

What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)

Minor

Is the economic impact due to the presence of the pest on the named host plant for planting, acceptable to the propagation and end user sectors concerned?

No

Conclusion:

Candidate

Justification:

6 - Are there feasible and effective measures available to prevent the presence of the pest on the plants for planting at an incidence above a certain threshold (including zero) to avoid an unacceptable economic impact as regards the relevant host plants?

Yes

Conclusion:

candidate

Justification:

7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?

Yes

Conclusion:

Candidate

Justification:

CONCLUSION ON THE STATUS:

Not recommended for listing as an RNQP: This pest/host/intended use combination meets all the criteria for RNQP status but the requirement for absence of visual symptoms on the traded material (current general 'Substantially free from' requirement in the EU) is considered to be sufficient.

EU COM (2015) Recommendation of the Working Group on the Annexes of the Council Directive 2000/29/EC – Section II – Listing of Harmful Organisms as regards the future listing of Ditylenchus destructor Thorne;